This invention relates generally to aircraft equipment and, in particular, to aircraft seating.
According to the General Aviation Crash Worthiness Project of the National Transportation Safety Board (“NTSB”), incidents of severe injuries and fatalities in survivable crashes of the general aviation fleet could be significantly improved by the use of energy absorbing seats and occupant restraints. According to one study conducted by the NTSB, many of the seats in the general aviation fleet broke or came off the seat tracks during survivable crashes. In one study, 44% of the occupied seats involved in general aviation crashes became detached from the airplane structure, usually because the seat legs broke or separated from their tracks. In many cases, warping of the cabin floor contributed to the failure of the seat structure.
The U.S. Code of Federal Regulations now requires impact simulation testing of aircrew seating for use in transportation category aircraft. The crash impact testing is performed by subjecting the seat to a simulated horizontal impact with a ground-level obstruction while the floor of the simulated aircraft is in a warped condition. For track mounted seats, which ordinarily have two parallel tracks, the requirement is that the simulated floor be warped so that the track on one side of the seat is skewed 10° vertically and the track on the opposite side is rolled 10° about its longitudinal axis. In many cases, the warped floor causes one of the seat track locking pins to disengage the seat track. This results in an unacceptable increase in the load that must be carried by the sole remaining seat track locking pin. What is needed, therefore, is a track-mounted aircraft seat having a locking mechanism that is capable of accommodating a warped floor during a crash.